The invention relates generally to an improved strand fabricating machine; also known in the art as a braiding machine.
More specifically, the invention relates to an apparatus for rotating a set of carriers for a strand supply bobbin relative to moving strands from a set of contra-rotating carriers for a strand supply bobbin.
A fair description of the purpose and use in a braiding machine of apparatus according to the invention is found in U.S. Pat. No. 1,888,477, 1932, Standish. Reference is made "to an improved method of driving the yarn supply carriers in a braiding machine . . . the rotary or circular orbit type of machine where the yarn from one set of supplies is passed either inside or outside of the yarn packages of a second set of supplies as are required to braid, and where both sets of supplies rotate in opposite directions about a common center." Standish discloses "improved means for passing yarn threads from one set of yarn supplies between a second set of yarn supply carriers moving in the opposite direction and the driving means for said second set." Standish uses "a rotary motion and discs having interrupted sectors and continuous sections substantially semi-circular in shape and adapted to secure interrupted contact with slots on said carriers and to maintain a continuous push or pull between the driving means and each of said carriers, and at the same time to allow ample clearance and time for passing the yarn between said driving means and carriers." (Col. 1, 11. 1-25).
An improvement by Standish on the rotary disc drive concept for moving one set of strand carriers relative to moving strands from a set of contra-rotating carriers is disclosed in U.S. Pat. No. 1,981,377, 1934. Standish II uses "substantially triangular shaped plates each having three projecting portions adapted to alternately make and break contact with a carrier". (Col. 1, 11. 21-24).
U.S. Pat. No. 3,892,161, 1975, Sokol, uses cam controlled pins or pivoting guide tubes 80 to direct wire or strand material from a set of outer bobbins 50 alternatively inwardly and outwardly relative to a moving set of inner bobbins 52.
U.S. Pat. No. 4,034,643, 1977, Iannucci, et al, drives the carriers 40 for an inner strand supply bobbin 20 by a mechanism 12 including pairs of dogs or pins 68 which alternately engage dual carrier slots 76, allowing passage by the moving outer strands 46 being guided by arms 48. A basic oscillating motion is imparted to the dogs 68 by pairs of bearing mounted shafts 62 each carrying a planetary gear 66 engaging a large circular gear 60. A crank 64 secured to each rotating shaft 62 is connected to a dog 68 through a linkage 80. The actual timing of rotation of each shaft 62 can be determined only by selecting the size and gearing of each of the circular gear 60 and planetary gear 66.
These and other prior art patents relating to rotary disc, cam controlled pin, and eccentric dog strand carrier drive mechanisms, for rotating one set of strand carriers relative to moving strands from another set of contra-rotating or stationary strand carriers, are to be found in Patent Office Class 87.
The prior art strand carrier drive mechanisms while effective, can fairly be characterized as involving components which have been costly to fabricate (eg. the gears 60 and 62 of Iannucci, et al), expensive to maintain (eg. the pivoting guide tubes 80 of Sokol), or have been both costly to fabricate and noisy to operate (eg. the rotary disc or lobed elements of Standish). Most of the prior art drive mechanisms have inherent sliding friction power losses.
So far as is known to the inventors, the art relating to braiding machine strand carrier rotatable mounting and drive mechanisms, whether inner-outer, upper-lower or front-rear, has not provided for articulated drive arms mounted on a single actuator post so that all carrier drive force is developed from a central point, has not had minimal sliding friction power loss factors, has not readily been capable of high speed operation at an acceptable noise level, and can not be fabricated and maintained at a relatively low cost.